Computing devices may be used to execute applications in a network environment. For example, a server computing device may execute one or more applications that interact with other devices via a network, or that interact with data received from network-accessible data stores. During operation, the applications may access various configuration parameters that control or otherwise affect the operation of the applications in some way. For example, certain configuration parameters may be used to control the level of detail that an application includes in a log file during execution. The configuration parameters may be stored in a separate parameter file or they may otherwise be externally modifiable. In this way, the configuration parameters can be accessed and changed without requiring changes to be made directly to the application source code or logic. For example, when a change to the level of log detail is desired, a system administrator may change a parameter value in a configuration file or other data store. The next time the application begins execution, it can read the configuration file and implement the desired change.